Have taken in a feral cats 4 week old kitten. Think will be 5 weeks tomorrow. Brought home Tuesday night and she has been eating kitten replacement formula. All seemed well, she was peeing in litter. Had first bm in litter on thursday afternoon, not too hard, not too soft. She was crying a bit when squatting in litter. Found out littermate had bladder infection. So brought her in to vets friday to check. She was 12 oz on friday, they seemed more concerned with the fact she wasn't pooping every day. So left her there for afternoon. When picked up her butt was so red and swollen and she had poop stuck to her fur. Once home her butt stayed sore, red and almost protruding. Had a couple rounds of diarrhea and the smell. My god, I've never smelt anything like it. Now she doesnt have diarrhea , just tries to poop and cries and has that foul smelling poop just hanging at her butt and in her fur. When I try to wipe it she goes crazy. I just picked up some bene-bac plus at the pet store. Will it help? She just today started eating royal canin baby cat soft food mixed with water. And I've started watering down her formula. I feel so bad for her.